An Experimental Study on the Piston Slap Motion Measurement during Real Operation of an IDI DIESEL Engine.

간접분사식 디젤엔진의 실운전중 피스톤 Slap 운동측정에 관한 실험적 연구

Piston slap is one of the major sources of noise in a 4-cycle diesel engine. Piston slap is not only one of major source mounted near the top and bottom of the piston thrust and antithrust skirts. Effects of engine speed, load and coolant temperature on piston motion were investigated. The measured piston motion showed 6 slapes per cycle resulting from the change of side force. Major piston slap timing was retarded as engine speeds became higher. The increase of engine load made large piston transverse movement toward thrust side of cylinder block. Piston transverse movement was due to reduced piston-liner clearance at higher coolant temperature.